Equilibrative Nucleoside Transporter 3 is an IFN-stimulated Gene that Facilitates Viral Genome Release

An increasing body of evidence emphasizes the role of metabolic reprogramming in immune cells to fight off infections. However, little is known about the regulation of metabolite transporters that facilitate and support metabolic demands. In this study, we found that the expression of Equilibrative Nucleoside Transporter 3 (ENT3, encoded by SoLute Carrier family 29 member 3, Slc29a3) is part of the innate immune response which is rapidly upregulated upon pathogen insults. The transcription of Slc29a3 is directly under the regulation of IFN-induced signaling, positioning this metabolite transporter as an Interferon-stimulated gene (ISG). Suprisingly, we unveil that several viruses, including SARS-CoV2, require ENT3 to facilitate their entry into the cytoplasm. The removal or suppression of ENT3 expression is sufficient to significantly decrease viral replication in vitro and in vivo. Our study reveals that ENT3 is a pro-viral ISG co-opted by some viruses for a survival advantage. Overall design: Bone marrow-derived macrophages generated from C57BL wild type and ENT3-/- mice were treated with or without 1000 U/mL IFN-ß for 4 hr, then harvested for RNA extraction. Each sample represents a biological replicate. The library was prepared by using Illumina TruSeq Stranded mRNA Sample Prep Kit and sequenced by Illumina NextSeq High Output Kit v2.5-75 cycles on the NextSeq 550 platform. The sequence was annotated according to Mus musculus GRCm38 mm10.